Not my pic, but this is in my city, Curitiba:
I used to visit that specific park (Parque Barigüi) fairly often, as I worked nearby. For me the fun part wasn't even interacting with the capybaras, but watching tourists interacting with them. Not recommended - unlike the ones in the OP, these here are wild and might have ticks, but... well, neither tourists nor capybaras give a fuck.
Just make sure that you don't go full "squeee" and chase them, they'll simply get into the water and you'll be sad. A girl whom I used to date did this.